Cationic steroidal antimicrobial compounds with endogenous groups

ABSTRACT

Cationic steroidal antimicrobial (CSA) compounds having a structure of Formula I, II or III, or salt thereof, wherein at least one of R 1 -R 18 , (e.g., R 18 ) includes a terpenyl group attached via an ester or amide linkage and at least one R 1 -R 18 , (e.g., R 3 , R 7  and R 12 ) is an amino acid linked to the steroidal backbone by an ester or amide linkage: 
     
       
         
         
             
             
         
       
         
         R 18  has the following structure: 
       
    
       —R 19 —(C═O)—X—R 20  
     where R 19  is omitted or alkyl, alkenyl, alkynyl, or aryl, X is oxygen or nitrogen, and R 20  is a terpenyl group.   R 3 , R 7  and R 12  have the following structure:   

       R 22 R 23 N—R 21 —(C═O)—X—
     where R 21  is substituted or unsubstituted alkyl, X is oxygen or nitrogen, and R 22  and R 23  are independently hydrogen, alkyl, alkenyl, alkynyl, or aryl.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/028,249, filed May 21, 2020, which is incorporated by reference inits entirety.

BACKGROUND OF THE INVENTION 1. Field

Disclosed are cationic steroidal antimicrobial (CSA) compounds,including CSA compounds having endogenous groups based on naturalterpenes, amino acids, and cholic acid or derivative of cholic acid, andmethods of manufacturing CSA compounds having endogenous groups.

2. Related Technology

Antimicrobial peptides are found in organisms ranging from mammals toamphibians to insects to plants. The ubiquity of antimicrobial peptideshas been used as evidence that these compounds do not readily engenderbacterial resistance. In addition, considering the varied sequences ofantimicrobial peptides among diverse organisms, it is apparent that theyhave evolved independently multiple times. Thus, antimicrobial peptidesappear to be one of “Nature's” primary means of controlling bacterialgrowth. For example, endogenous antimicrobial peptides, such as thehuman cathelicidin LL-37, play key roles in innate immunity. LL-37 isfound in airway mucus and is believed to be important in controllingbacterial growth in the lung. However, clinical use of antimicrobialpeptides presents significant issues including the relatively high costof producing peptide-based therapeutics, the susceptibility of peptidesto proteases generated by the host and by bacterial pathogens, anddeactivation of antimicrobial peptides by proteins and DNA in lungmucosa.

An attractive means of harnessing the antibacterial activities ofantimicrobial peptides without the issues delineated above is to developnon-peptide mimics of antimicrobial peptides that display similarbroad-spectrum antibacterial activity utilizing the same or similarmechanism of action. Non-peptide mimics would offer lower-cost synthesisand potentially increased stability to proteolytic degradation. Inaddition, control of water solubility and charge density may be used tocontrol association with proteins and DNA in lung mucosa.

With over 1,600 examples of known antimicrobial peptides, it is possibleto categorize the structural features common to them. While the primarysequences of these peptides vary substantially, morphologies adopted bya vast majority are similar. Those that adopt alpha helix conformationsjuxtapose hydrophobic side chains on one face of the helix with cationic(positively charged) side chains on the opposite side. Similarmorphology is found in antimicrobial peptides that form beta sheetstructures: hydrophobic side chains on one face of the sheet andcationic side chains on the other.

Examples of small molecule, non-peptide mimics of antimicrobialpeptides, include steroidal compounds known as “ceragenins,” examples ofwhich are “CSA-13” and “CSA-44”, which can reproduce the amphiphilicmorphology in antimicrobial peptides. A problem that remains is that CSAcompounds have side groups that form non-endogenous degradation productsthat may not be approved for the human body and/or which are notentirely safe at higher concentrations. Another problem is that CSAcompounds often require complex, multi-step reaction sequences for theirmanufacture. Every additional step in the manufacture of CSA compoundsincreases cost and reduces overall product yield.

SUMMARY

Disclosed herein is a new class of cationic steroidal antimicrobial(CSA) compounds with endogenous groups attached to an endogenous sterolbackbone. This class of CSA compounds is referred to as “endogenous CSAcompounds”.

The degradation products of endogenous CSA compounds are themselvesendogenous, such as cholic acid (a common bile acid), amino acids, e.g.,beta-alanine (an endogenous neurotransmitter and amino acid), andnatural terpenes, e.g., geraniol (a natural terpene found in higherorganisms and some edible plants). The endogenous CSA compounds arerelatively easy and inexpensive to manufacture and yet possess desiredantimicrobial, anti-inflammatory, and other desirable properties.

The CSA compounds disclosed herein can have a structure of Formula I, IIor III, or a salt thereof, having a steroidal backbone, and wherein atleast one of R₁-R₁₈, preferably R₁₈, can include a terpenyl group, suchas a geranyl group, at the C-24 position of the steroidal backbone, andat least one of R₁-R₁₈, preferably at least one of R₃, R₇ and R₁₂, cancomprise an amino acid linked to the sterol backbone by an ester linkageat the C3, C7 and/or C12 positions(s):

In embodiments, at least one of R₁-R₁₈, preferably R₁₈, can have thefollowing structure:

—R₁₉—(C═O)—O—R₂₀

where R₁₉ is omitted or is selected from alkyl, alkenyl, alkynyl, andaryl, and R₂₀ is a terpenyl group that forms a terpenyl ester, such asgeranyl ester, which forms a natural terpene, such as geraniol, asdegradation product (e.g., by hydrolysis of the ester group at the C24position). The terpenyl group can be attached at the C24 position (orelsewhere) by other linkages, such as reverse ester linkage (which formsgeranoic acid, another natural terpene, as degradation product), amide,ether, or amine linkage.

In embodiments, at least one of R₁-R₁₈, preferably at least one of R₃,R₇ and R₁₂, can have the following aminoalkylcarboxy structure:

R₂₂R₂₃N—R₂₁—(C═O)—O—

where R₂₁ is a substituted or unsubstituted alkyl and R₂₂ and R₂₃ areindependently selected from hydrogen, alkyl, alkenyl, alkynyl, and aryl.At least one of R₃, R₇ and R₁₂, preferably two or three of R₃, R₇ andR₁₂, is/are an ester group of an amino acid, such as beta-alanine, whichforms an endogenous amino acid (e.g., beta-alanine) as degradationproduct (e.g., by hydrolysis of the ester group(s) at the C3, C7 and/orC12 position(s)). Alternatively, the aminoalkyl group of at least one ofR₃, R₇ and R₁₂ can be attached to one or more of the C3, C7 and/or C12positions (or elsewhere) by other linkages, such as amide or etherlinkage.

A non-limiting example of an endogenous CSA compound that formsendogenous degradation products by hydrolysis of ester groups isCSA-148, and salts thereof:

The degradation products of CSA-148, and salts thereof, are endogenousmolecules:

In embodiments, a method of manufacturing an endogenous CSA compoundwith ester linkages includes: (1) reacting the C24 acid group of cholicacid with a terpene (e.g., geraniol) or terpene derivative with aleaving group (e.g., geranyl bromide) in one or more steps to form aterpenyl ester (e.g., geranyl ester) at the C24 position of R₁₈, and (2)reacting at least one of the hydroxyl groups at the C3, C7 and C12positions of cholic acid with an optionally protected amino acid (e.g.,optionally protected beta-alanine) in one or more steps to form an esterlinkage, which links at least one of R₃, R₇ and R₁₂ to the sterolbackbone to yield a desired CSA compound.

Advantages of endogenous CSA compounds disclosed herein include, but arenot limited to, forming endogenous degradation products, such as cholicacid, an amino acid, such as beta-alanine, and a natural terpene, suchas geraniol, and providing comparable and/or improved antimicrobialactivity, anti-inflammatory activity, and other desired propertiescompared to existing CSA compounds and/or simplified synthesis of CSAcompounds and/or intermediate CSA compounds compared to existingsynthetic routes.

Additional features and advantages will be set forth in part in thedescription that follows, and in part will be obvious from thedescription, or may be learned by practice of the embodiments disclosedherein. It is to be understood that both the foregoing brief summary andthe following detailed description are exemplary and not restrictive ofthe embodiments disclosed herein or as claimed.

DETAILED DESCRIPTION

Disclosed herein is a new class of cationic steroidal antimicrobial(CSA) compounds with endogenous groups attached to an endogenous sterolbackbone. This class of CSA compounds is referred to as “endogenous CSAcompounds”.

The degradation products of endogenous CSA compounds are themselvesendogenous, such as cholic acid (a common bile acid), amino acids, suchas beta-alanine (an endogenous neurotransmitter and amino acid), andnatural terpene, such as geraniol (a terpene found in higher organismsand some edible plants). The endogenous CSA compounds are relativelyeasy and inexpensive to manufacture and yet possess desiredantimicrobial, anti-inflammatory, and other desirable properties.

Definitions

Any “R” groups such as, without limitation, R₁, R₂, R₃, R₄, R₅, R₆, R₇,R₈, R₉, R₁₀, R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, and R₁₈, representsubstituents that can be attached to the sterol backbone. Unlessotherwise specified, an R group may be substituted or unsubstituted.

A “ring” can be heterocyclic or carbocyclic. “Saturated” means a ring inwhich each atom is either hydrogenated or substituted such that thevalency of each atom is filled. “Unsaturated” means a ring where thevalency of each atom of the ring may not be filled with hydrogen orother substituents. For example, adjacent carbon atoms in a fused ringcan be double bonded to each other. Unsaturation can also includedeleting at least one of the following pairs and completing the valencyof the ring carbon atoms at these deleted positions with a double bond,such as R₅ and R₉; R₈ and R₁₀; and R₁₃ and R₁₄.

Where a group is “substituted” it may be substituted with one, two,three or more of the indicated substituents, which may be the same ordifferent, each replacing a hydrogen atom. If no substituents areindicated, the indicated “substituted” group may be substituted with oneor more groups individually and independently selected from alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, acylalkyl,alkoxyalkyl, aminoalkyl, amino acid, aryl, heteroaryl, heteroalicyclyl,aralkyl, heteroaralkyl, (heteroalicyclyl)alkyl, hydroxy, protectedhydroxyl, alkoxy, aryloxy, acyl, mercapto, alkylthio, arylthio, cyano,halogen (e.g., F, Cl, Br, and I), thiocarbonyl, O-carbamyl, N-carbamyl,O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido,N-sulfonamido, C-carboxy, protected C-carboxy, O-carboxy, isocyanato,thiocyanato, isothiocyanato, nitro, oxo, silyl, sulfenyl, sulfinyl,sulfonyl, haloalkyl, haloalkoxy, trihalomethanesulfonyl,trihalomethanesulfonamido, an amino, a mono-substituted amino group anda di-substituted amino group, R_(a)O(CH₂)_(m)O—,R_(b)(CH₂)_(n)O—R_(c)C(O)O(CH₂)_(p)O—, and protected derivativesthereof. The substituent may be attached to the group at more than oneattachment point. For example, an aryl group may be substituted with aheteroaryl group at two attachment points to form a fused multicyclicaromatic ring system. Biphenyl and naphthalene are two examples of anaryl group that is substituted with a second aryl group. A group that isnot specifically labeled as substituted or unsubstituted may beconsidered to be either substituted or unsubstituted.

The terms “C_(a)” or “C_(a) to C_(b)” in which “a” and “b” are integersrefer to the number of carbon atoms in an alkyl, alkenyl or alkynylgroup, or the number of carbon atoms in the ring of a cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl or heteroalicyclyl group.That is, the alkyl, alkenyl, alkynyl, ring of the cycloalkyl, ring ofthe cycloalkenyl, ring of the cycloalkynyl, ring of the aryl, ring ofthe heteroaryl or ring of the heteroalicyclyl can contain from “a” to“b”, inclusive, carbon atoms. Thus, for example, a “C₁ to C₄ alkyl”group refers to all alkyl groups having 1 to 4 carbons, that is, CH₃—,CH₃CH₂—, CH₃CH₂CH₂—, (CH₃)₂CH—, CH₃CH₂CH₂CH₂—, CH₃CH₂CH(CH₃)—,(CH₃)₂CHCH₂— and (CH₃)₃C—. If no “a” and “b” are designated with regardto an alkyl, alkenyl, alkynyl, cycloalkyl cycloalkenyl, cycloalkynyl,aryl, heteroaryl or heteroalicyclyl group, the broadest range describedin these definitions is to be assumed.

“Alkyl” refers to a straight or branched hydrocarbon chain thatcomprises a fully saturated (no double or triple bonds) hydrocarbongroup. The alkyl group may have 1 to 25 carbon atoms (whenever itappears herein, a numerical range such as “1 to 25” refers to eachinteger in the given range; e.g., “1 to 25 carbon atoms” means that thealkyl group may consist of 1 carbon atom, 2 carbon atoms, 3 carbonatoms, etc., up to and including 25 carbon atoms, although the presentdefinition also covers the occurrence of the term “alkyl” where nonumerical range is designated). The alkyl group may also be a mediumsize alkyl having 1 to 15 carbon atoms. The alkyl group could also be alower alkyl having 1 to 6 carbon atoms. The alkyl group of the compoundsmay be designated as “C₄” or “C₁-C₄ alkyl” or similar designations. Byway of example only, “C₁-C₄ alkyl” indicates that there are one to fourcarbon atoms in the alkyl chain, i.e., the alkyl chain is selected frommethyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, andt-butyl. Typical alkyl groups include, but are in no way limited to,methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl,pentyl and hexyl. The alkyl group may be substituted or unsubstituted.

“Alkenyl” refers to an alkyl group that contains in the straight orbranched hydrocarbon chain one or more double bonds. The alkenyl groupmay have 2 to 25 carbon atoms (whenever it appears herein, a numericalrange such as “2 to 25” refers to each integer in the given range; e.g.,“2 to 25 carbon atoms” means that the alkenyl group may consist of 2, 3,or 4 carbon atoms, etc., up to and including 25 carbon atoms, althoughthe present definition also covers the occurrence of the term “alkenyl”where no numerical range is designated). The alkenyl group may also be amedium size alkenyl having 2 to 15 carbon atoms. The alkenyl group couldalso be a lower alkenyl having 1 to 6 carbon atoms. The alkenyl group ofthe compounds may be designated as “C₄” or “C₂-C₄ alkenyl” or similardesignations. An alkenyl group may be unsubstituted or substituted.

“Alkynyl” refers to an alkyl group that contains in the straight orbranched hydrocarbon chain one or more triple bonds. The alkynyl groupmay have 2 to 25 carbon atoms (whenever it appears herein, a numericalrange such as “2 to 25” refers to each integer in the given range; e.g.,“2 to 25 carbon atoms” means that the alkynyl group may consist of 2, 3,or 4 carbon atoms, etc., up to and including 25 carbon atoms, althoughthe present definition also covers the occurrence of the term “alkynyl”where no numerical range is designated). The alkynyl group may also be amedium size alkynyl having 2 to 15 carbon atoms. The alkynyl group couldalso be a lower alkynyl having 2 to 6 carbon atoms. The alkynyl group ofthe compounds may be designated as “C₄” or “C₂-C₄ alkynyl” or similardesignations. An alkynyl group may be unsubstituted or substituted.

“Aryl” refers to a carbocyclic (all carbon) monocyclic or multicyclicaromatic ring system (including fused ring systems where two carbocyclicrings share a chemical bond) that has a fully delocalized pi-electronsystem throughout all the rings. The number of carbon atoms in an arylgroup can vary. For example, the aryl group can be a C₆-C₁₄ aryl group,a C₆-C₁₀ aryl group, or a C₆ aryl group (although the definition ofC₆-C₁₀ aryl covers the occurrence of “aryl” when no numerical range isdesignated). Examples of aryl groups include, but are not limited to,benzene, naphthalene and azulene. An aryl group may be substituted orunsubstituted.

“Aralkyl” and “aryl(alkyl)” refer to an aryl group connected, as asubstituent, via a lower alkylene group. The aralkyl group may have 6 to20 carbon atoms (whenever it appears herein, a numerical range such as“6 to 20” refers to each integer in the given range; e.g., “6 to 20carbon atoms” means that the aralkyl group may consist of 6 carbon atom,7 carbon atoms, 8 carbon atoms, etc., up to and including 20 carbonatoms, although the present definition also covers the occurrence of theterm “aralkyl” where no numerical range is designated). The loweralkylene and aryl group of an aralkyl may be substituted orunsubstituted. Examples include but are not limited to benzyl,2-phenylalkyl, 3-phenylalkyl, and naphthylalkyl.

“Lower alkylene groups” refers to a C₁-C₂₅ straight-chained alkyltethering groups, such as —CH₂— tethering groups, forming bonds toconnect molecular fragments via their terminal carbon atoms. Examplesinclude but are not limited to methylene (—CH₂—), ethylene (—CH₂CH₂—),propylene (—CH₂CH₂CH₂—), and butylene (—CH₂CH₂CH₂CH₂—). A lower alkylenegroup can be substituted by replacing one or more hydrogen of the loweralkylene group with a substituent(s) listed under the definition of“substituted.”

“Cycloalkyl” refers to a completely saturated (no double or triplebonds) mono- or multi-cyclic hydrocarbon ring system. When composed oftwo or more rings, the rings may be joined together in a fused fashion.Cycloalkyl groups can contain 3 to 10 atoms in the ring(s) or 3 to 8atoms in the ring(s). A cycloalkyl group may be unsubstituted orsubstituted. Typical cycloalkyl groups include, but are in no waylimited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl and cyclooctyl.

“Cycloalkenyl” refers to a mono- or multi-cyclic hydrocarbon ring systemthat contains one or more double bonds in at least one ring; although,if there is more than one, the double bonds cannot form a fullydelocalized pi-electron system throughout all the rings (otherwise thegroup would be “aryl,” as defined herein). When composed of two or morerings, the rings may be connected together in a fused fashion. Acycloalkenyl group may be unsubstituted or substituted.

“Cycloalkynyl” refers to a mono- or multi-cyclic hydrocarbon ring systemthat contains one or more triple bonds in at least one ring. If there ismore than one triple bond, the triple bonds cannot form a fullydelocalized pi-electron system throughout all the rings. When composedof two or more rings, the rings may be joined together in a fusedfashion. A cycloalkynyl group may be unsubstituted or substituted.

“Alkoxy” or “alkyloxy” refer to the formula —OR wherein R is an alkyl,an alkenyl, an alkynyl, a cycloalkyl, a cycloalkenyl or a cycloalkynylas defined above. A non-limiting list of alkoxys are methoxy, ethoxy,n-propoxy, 1-methylethoxy (isopropoxy), n-butoxy, iso-butoxy, sec-butoxyand tert-butoxy. An alkoxy may be substituted or unsubstituted.

“Acyl” refers to a hydrogen, alkyl, alkenyl, alkynyl, aryl, orheteroaryl connected, as substituents, via a carbonyl group, such as—(C═O)—R. Examples include formyl, acetyl, propanoyl, benzoyl, andacryl. An acyl may be substituted or unsubstituted.

“Alkoxyalkyl” or “alkyloxyalkyl” refer to an alkoxy group connected, asa substituent, via a lower alkylene group. Examples includealkyl-O-alkyl- and alkoxy-alkyl- with the terms alkyl and alkoxy definedherein.

“Hydroxyalkyl” refers to an alkyl group in which one or more of thehydrogen atoms are replaced by a hydroxy group. Exemplary hydroxyalkylgroups include but are not limited to, 2-hydroxy ethyl, 3-hydroxypropyl,2-hydroxypropyl, and 2,2-dihydroxy ethyl. A hydroxyalkyl may besubstituted or unsubstituted.

“Haloalkyl” refers to an alkyl group in which one or more of thehydrogen atoms are replaced by a halogen (e.g., mono-haloalkyl,di-haloalkyl and tri-haloalkyl). Examples include chloromethyl,fluoromethyl, difluoromethyl, trifluoromethyl and1-chloro-2-fluoromethyl, 2-fluoroisobutyl. A haloalkyl may besubstituted or unsubstituted.

“Amino” refers to “—NH₂”.

“Hydroxy” refers to “—OH”.

“Cyano” refers to “—CN”.

“Carbonyl” or “oxo” refer to “—C═O”.

“Azido” refers to “—N₃”.

“Aminoalkyl” refers to an amino group connected, as a substituent, via alower alkylene group. Examples include H₂N-alkyl- with the term alkyldefined herein.

“Alkylcarboxyalkyl” refers to an alkyl group connected, as asubstituent, to a carboxy group that is connected, as a substituent, toan alkyl group. Examples include alkyl-(C═O)—O-alkyl- andalkyl-O—(C═O)-alkyl- with the term alkyl as defined herein.

“Alkylaminoalkyl” refers to an alkyl group connected, as a substituent,to an amino group that is connected, as a substituent, to an alkylgroup. Examples include alkyl-NH-alkyl- with the term alkyl as definedherein.

“Dialkylaminoalkyl” and “di(alkyl)aminoalkyl” refer to two alkyl groupsconnected, each as a substituent, to an amino group that is connected,as a substituent, to an alkyl group. Examples include

with the term alkyl as defined herein.

“Alkylaminoalkylamino” refers to an alkyl group connected, as asubstituent, to an amino group that is connected, as a substituent, toan alkyl group that is connected, as a substituent, to an amino group.Examples include alkyl-NH-alkyl-NH— with the term alkyl as definedherein.

“Alkylaminoalkylaminoalkylamino” refers to an alkyl group connected, asa substituent, to an amino group that is connected, as a substituent, toan alkyl group that is connected, as a substituent, to an amino groupthat is connected, as a substituent, to an alkyl group. Examples includealkyl-NH-alkyl-NH-alkyl- with the term alkyl as defined herein.

“Arylaminoalkyl” refers to an aryl group connected, as a substituent, toan amino group that is connected, as a substituent, to an alkyl group.Examples include aryl-NH-alkyl- with the terms aryl and alkyl as definedherein.

“Aminoalkyloxy” refers to an amino group connected, as a substituent, toan alkyloxy group. Examples include H₂N-alkyl-O— and H₂N-alkoxy- withthe terms alkyl and alkoxy as defined herein.

“Aminoalkyloxyalkyl” refers to an amino group connected, as asubstituent, to an alkyloxy group connected, as a substituent, to analkyl group. Examples include H₂N-alkyl-O-alkyl- and H₂N-alkoxy-alkyl-with the terms alkyl and alkoxy as defined herein.

“Aminoalkylcarboxy” refers to an amino group connected, as asubstituent, to an alkyl group connected, as a substituent, to a carboxygroup. Examples include H₂N-alkyl-(C═O)—O— and H₂N-alkyl-O—(C═O)— withthe term alkyl as defined herein.

“Aminoalkylaminocarbonyl” refers to an amino group connected, as asubstituent, to an alkyl group connected, as a substituent, to an aminogroup connected, as a substituent, to a carbonyl group. Examples includeH₂N-alkyl-NH—(C═O)— with the term alkyl as defined herein.

“Aminoalkylcarboxamido” refers to an amino group connected, as asubstituent, to an alkyl group connected, as a substituent, to acarbonyl group connected, as a substituent to an amino group. Examplesinclude H₂N-alkyl-(C═O)—NH— and H₂N-alkyl-NH—(C═O)— with the term alkylas defined herein.

“Azidoalkyloxy” refers to an azido group connected as a substituent, toan alkyloxy group. Examples include N₃-alkyl-O— and N₃-alkoxy- with theterms alkyl and alkoxy as defined herein.

“Cyanoalkyloxy” refers to a cyano group connected as a substituent, toan alkyloxy group. Examples include NC-alkyl-O— and NC-alkoxy- with theterms alkyl and alkoxy as defined herein.

“Sulfenyl” refers to “—SR” in which R can be hydrogen, alkyl, alkenyl,alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heteroalicyclyl, aralkyl, or (heteroalicyclyl)alkyl. A sulfenyl may besubstituted or unsubstituted.

“Sulfinyl” refers to “—(S═O)—R” in which R can be the same as definedwith respect to sulfenyl. A sulfinyl may be substituted orunsubstituted.

“Sulfonyl” refers to “—(S═O)—OR” in which R can be the same as definedwith respect to sulfenyl. A sulfonyl may be substituted orunsubstituted.

“O-carboxy” refers to “R—(C═O)—O—” in which R can be hydrogen, alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl,heteroaryl, heteroalicyclyl, aralkyl, or (heteroalicyclyl)alkyl, asdefined herein. An O-carboxy may be substituted or unsubstituted.

“Ester” and “C-carboxy” refer to “—(C═O)—OR” in which R can be the sameas defined with respect to O-carboxy. An ester and C-carboxy may besubstituted or unsubstituted.

“Thiocarbonyl” refers to “—(C═S)—R” in which R can be the same asdefined with respect to O-carboxy. A thiocarbonyl may be substituted orunsubstituted.

“Trihalomethanesulfonyl” refers to “X₃CSO₂—” wherein X is a halogen.

“S-sulfonamido” refers to “—SO₂N(RARB)” in which RA and RB can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An S-sulfonamido may be substituted orunsubstituted.

“N-sulfonamido” refers to “RSO₂N(RA)-” in which R and RA can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An N-sulfonamido may be substituted orunsubstituted.

“O-carbamyl” and “urethanyl” refer to “—O—(C═O)—N(RARB)” in which RA andRB can be independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An O-carbamyl or urethanyl may be substitutedor unsubstituted.

“N-carbamyl” refers to “RO—(C═O)—N(RA)-” in which R and RA can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An N-carbamyl may be substituted orunsubstituted.

“O-thiocarbamyl” refers to “—O—(C═S)—N(RARB)” in which RA and RB can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An O-thiocarbamyl may be substituted orunsubstituted.

“N-thiocarbamyl” refers to “RO—(C═S)—N(RA)-” in which R and RA can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An N-thiocarbamyl may be substituted orunsubstituted.

C-amido” refers to “—(C═O)—N(RARB)” in which RA and RB can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. A C-amido may be substituted orunsubstituted.

“N-amido” refers to “R—(C═O)—N(RA)-” in which R and RA can beindependently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heteroalicyclyl, aralkyl,or (heteroalicyclyl)alkyl. An N-amido may be substituted orunsubstituted.

“Guanidinoalkyloxy” refers to a guanidinyl group connected, as asubstituent, to an alkyloxy group. Examples include

with the terms alkyl and alkoxy as defined herein.

“Guanidinoalkylcarboxy” refers to a guanidinyl group connected, as asubstituent, to an alkyl group connected, as a substituent, to a carboxygroup. Examples include

with the term alkyl as defined herein.

“Quaternary ammonium alkylcarboxy” refers to a quaternized amino groupconnected, as a substituent, to an alkyl group connected, as asubstituent, to a carboxy group. Examples include

with the term alkyl as defined herein.

“Halogen atom” and “halogen” mean any one of the radio-stable atoms ofcolumn 7 of the Periodic Table of the Elements, such as, fluorine,chlorine, bromine and iodine.

Where the number of substituents is not specified (e.g. haloalkyl),there may be one or more substituents present. For example, “haloalkyl”may include one or more of the same or different halogens.

“Amino acid” refers to any amino acid (both standard and non-standardamino acids), including, but not limited to, α-amino acids, β-aminoacids, γ-amino acids and δ-amino acids. Examples of suitable amino acidsinclude, but are not limited to, alanine, asparagine, aspartate,cysteine, glutamate, glutamine, glycine, proline, serine, tyrosine,arginine, histidine, isoleucine, leucine, lysine, methionine,phenylalanine, threonine, tryptophan and valine. Additional examples ofsuitable amino acids include, but are not limited to, ornithine,hypusine, 2-aminoisobutyric acid, dehydroalanine, γ-aminobutyric acid,citrulline, β-alanine, α-ethyl-glycine, α-propyl-glycine and norleucine.

A linking group is a divalent moiety used to link one steroid to anothersteroid. In embodiments, the linking group is used to link a first CSAwith a second CSA (which may be the same or different). An example of alinking group is (C₁-C₁₀) alkyloxy-(C₁-C₁₀) alkyl.

“P.G.” or “protecting group” or “protecting groups” refer to any atom orgroup of atoms that is added to a molecule in order to prevent existinggroups in the molecule from undergoing unwanted chemical reactions.Examples of protecting group moieties are described in T. W. Greene andP. G. M. Wuts, Protective Groups in Organic Synthesis, 3. Ed. John Wiley& Sons, 1999, and in J. F. W. McOmie, Protective Groups in OrganicChemistry Plenum Press, 1973, both of which are hereby incorporated byreference for the limited purpose of disclosing suitable protectinggroups. The protecting group moiety may be chosen in such a way, thatthey are stable to certain reaction conditions and readily removed at aconvenient stage using methodology known from the art. A non-limitinglist of protecting groups include benzyl; substituted benzyl;alkylcarbonyls and alkoxycarbonyls (e.g., t-butoxycarbonyl (BOC),acetyl, or isobutyryl); arylalkylcarbonyls and arylalkoxycarbonyls(e.g., benzyloxycarbonyl); substituted methyl ether (e.g. methoxymethylether); substituted ethyl ether; substituted benzyl ether;tetrahydropyranyl ether; silyls (e.g., trimethylsilyl, triethylsilyl,triisopropylsilyl, t-butyldimethylsilyl, tri-iso-propylsilyloxymethyl,[2-(trimethylsilyl)ethoxy]methyl or t-butyldiphenylsilyl); esters (e.g.benzoate ester); carbonates (e.g. methoxymethylcarbonate); sulfonates(e.g. tosylate or mesylate); acyclic ketal (e.g. dimethyl acetal);cyclic ketals (e.g., 1,3-dioxane, 1,3-dioxolanes, and those describedherein); acyclic acetal; cyclic acetal (e.g., those described herein);acyclic hemiacetal; cyclic hemiacetal; cyclic dithioketals (e.g.,1,3-dithiane or 1,3-dithiolane); orthoesters (e.g., those describedherein) and triarylmethyl groups (e.g., trityl; monomethoxytrityl(MMTr); 4,4′-dimethoxytrityl (DMTr); 4,4′,4″-trimethoxytrityl (TMTr);and those described herein). Amino-protecting groups are known to thoseskilled in the art. In general, the species of protecting group is notcritical, provided that it is stable to the conditions of any subsequentreaction(s) on other positions of the compound and can be removed at theappropriate point without adversely affecting the remainder of themolecule. In addition, a protecting group may be substituted for anotherafter substantive synthetic transformations are complete. Clearly, wherea compound differs from a compound disclosed herein only in that one ormore protecting groups of the disclosed compound has been substitutedwith a different protecting group, that compound is within thedisclosure.

CSA Compounds:

Cationic steroidal anti-microbial (CSA) compounds, also referred to as“CSA compounds”, “CSAs”, CSA molecules or “ceragenin” compounds, aresynthetically produced, small molecule chemical compounds that include asterol backbone having various charged groups (e.g., amine and cationicgroups) attached to the backbone. The sterol backbone can be used toorient amine or guanidine groups on a face or plane of the sterolbackbone. CSAs are cationic and amphiphilic, based upon the functionalgroups attached to the backbone. They are facially amphiphilic with ahydrophobic face and a polycationic face.

Without wishing to be bound to theory, CSA molecules described hereinact as anti-microbial agents (e.g., anti-bacterial, anti-fungal, andanti-viral). It is believed, for example, that anti-microbial CSAmolecules may act as an antimicrobial by binding to the cellularmembrane of bacteria and other microbes and modifying the cell membrane,e.g., such as by forming a pore that allows the leakage of ions andcytoplasmic materials critical to the microbe's survival, and leading tothe death of the affected microbe. In addition, anti-microbial CSAmolecules may also act to sensitize bacteria to other antibiotics. Forexample, at concentrations of anti-microbial CSA molecules below thecorresponding minimum bacteriostatic concentration (MIC), the CSAcompound may cause bacteria to become more susceptible to otherantibiotics by disrupting the cell membrane, such as by increasingmembrane permeability. It is postulated that charged cationic groups maybe responsible for disrupting the bacterial cellular membrane andimparting anti-microbial properties. CSA molecules may have similarmembrane- or outer coating-disrupting effects on fungi and viruses.

By way of background, exemplary CSA compounds and methods for theirmanufacture are described in U.S. Pat. Nos. 6,350,738, 6,486,148,6,767,904, 7,598,234, 7,754,705, 8,691,252, 8,975,310, 9,434,759,9,527,883, 9,943,614, 10,155,788, 10,227,376, 10,370,403, and10,626,139, U.S. Pat. Pub. Nos. 2016/0311850 and 2017/0210776, and U.S.Prov. App. No. 63/025,255, which are incorporated herein by reference.The skilled artisan will recognize the compounds within the genericformulae set forth herein and understand their preparation in view ofthe references cited herein and the Examples.

The compounds and compositions disclosed herein are optionally preparedas salts, which advantageously makes them cationic when one or moreamine groups is/are protonated. The term “salt” as used herein is abroad term, and is to be given its ordinary and customary meaning to askilled artisan (and is not to be limited to a special or customizedmeaning), and refers without limitation to a salt of a compound. Inembodiments, the salt is an acid addition salt of the compound. Saltscan be obtained by reacting a compound with inorganic acids such ashydrohalic acid (e.g., hydrochloric acid or hydrobromic acid), sulfuricacid, nitric acid, phosphoric acid, and phosphonic acid. Salts can alsobe obtained by reacting a compound with an organic acid such asaliphatic or aromatic carboxylic or sulfonic acids, sulfinic acids, forexample formic acid, acetic acid, propionic acid, glycolic acid, pyruvicacid, malonic acid, maleic acid, fumaric acid, trifluoroacetic acid,benzoic acid, cinnamic acid, mandelic acid, succinic acid, lactic acid,malic acid, tartaric acid, citric acid, ascorbic acid, nicotinic acid,methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid,salicylic acid, stearic acid, muconic acid, butyric acid, phenylaceticacid, phenylbutyric acid, valproic acid, 1,2-ethanedisulfonic acid,2-hydroxyethanesulfonic acid, benzenesulfonic acid,2-naphthalenesulfonic acid, or 1,5-naphthalenedisulfonic acid. Salts canalso be obtained by reacting a compound with a base to form a salt suchas an ammonium salt, an alkali metal salt, such as a lithium, sodium ora potassium salt, an alkaline earth metal salt, such as a calcium,magnesium or aluminum salt, a salt of organic bases such asdicyclohexylamine, N-methyl-D-glucamine, tris(hydroxymethyl)methylamine,C₁-C₇ alkylamine, cyclohexylamine, dicyclohexylamine, triethanolamine,ethylenediamine, ethanolamine, diethanolamine, triethanolamine,tromethamine, and salts with amino acids such as arginine and lysine; ora salt of an inorganic base, such as aluminum hydroxide, calciumhydroxide, potassium hydroxide, sodium carbonate, sodium hydroxide, orthe like.

In embodiments, the salt is a hydrochloride salt. In embodiments, thesalt is a mono-hydrochloride salt, a di-hydrochloride salt, atri-hydrochloride salt, or a tetra-hydrochloride salt. Additionalexamples of salts include sulfuric acid addition salts, sulfonic acidaddition salts, disulfonic acid addition salts,1,5-naphthalenedisulfonic acid addition salts, sulfate salts, andbisulfate salts.

The CSA compounds disclosed herein can have a structure of Formula I, IIor III, or a salt thereof, having a steroidal backbone, and wherein atleast one of R₁-R₁₈, preferably R₁₈, can include a terpenyl group, suchas a geranyl group at the C24 position of the steroidal backbone, and atleast one of R₁-R₁₈, preferably at least one of R₃, R₇ and R₁₂, cancomprise an amino acid linked to the sterol backbone by an ester linkageat the C3, C7 and/or C12 positions(s):

In embodiments, at least one of R₁-R₁₈, preferably R₁₈, can have thefollowing structure:

—R₁₉—(C═O)—O—R₂₀

where R₁₉ is omitted or is selected from alkyl, alkenyl, alkynyl, andaryl, and R₂₀ is a terpenyl group that forms a terpenyl ester, such asgeranyl ester, which forms a natural terpene, such as geraniol, asdegradation product (e.g., by hydrolysis of the ester group at the C24position).

The empirical formula of geraniol is C₁₀H₁₈O and its chemical structureis:

It is within the scope of the invention to use other terpenyl groupsthat form natural terpenes as degradation products, such as isomers,analogs, and derivatives of geraniol. Below are examples of otheralcohol terpenes that can provide terpenyl group R₂₀.

Nerol is the cis-isomer of geraniol (the trans-isomer) having theempirical formula C₁₀H₁₈O and the chemical structure:

8-hydroxygeraniol has the empirical formula C₁₀H₁₈O₂ and the chemicalstructure:

Farnesol has the empirical formula C₁₅H₂₆O and the chemical structure:

Geranylgeraniol has the empirical formula C₂₀H₃₄O and the chemicalstructure:

Geranylfarnesol has the empirical formula C₂₅H₄₂O and the chemicalstructure:

Prenol has the empirical formula C₅H₁₀O, the chemical structure below,and is the building block of polyprenols having the general formulaH—[CH₂CCH₃═CHCH₂)_(n))—OH, such as geranial, farnesol, geranylgeraniol,and geranylfarnesol mentioned above:

Linalool has the empirical formula C₁₀H₁₈O and the chemical structure:

Nerolidol, including trans-nerolidol and cis-nerolidol, has theempirical formula C₁₅H₂₆O and the chemical structures:

Rhodinol has the empirical formula C₁₀H₂₀O and the chemical structure:

Phytol has the empirical formula C₂₀H₄₀O and the chemical structure:

Isophytol has the empirical formula C₂₀H₄₀O and the chemical structure:

Phytantriol has the empirical formula C₂₀H₄₀O and the chemicalstructure:

Citronellol, including (+)-citronellol and (−)-citronellol, has theempirical formula C₁₀H₂₀O and the following chemical structures:

Alpha-bisabolol has the empirical formula C₁₅H₂₆O and the chemicalstructure:

Retinol (Vitamin A) has the empirical formula C₂₀H₃₀O and the chemicalstructure:

Terpineols, including α-terpineol, β-terpineol, γ-terpineol,δ-terpineol, and 4-terpineol, have the empirical formula C₁₀H₁₈O and thechemical structures:

Natural menthol, (−)-Menthol, and its isomers, have the empiricalformula C₁₀H₂₀O and the chemical structures:

Fenchol has the empirical formula C₁₀H₁₈O and the chemical structure:

Cafestol has the empirical formula C₂₀H₂₈O₃ and the chemical structure:

Kahweol has the empirical formula C₂₀H₂₆O₃ and the chemical structure:

The terpenyl group can be attached to the sterol backbone by linkagesother than the ester linkage defined above, such as reverse ester (inwhich the terpenyl is attached to the carbonyl and which would formterpenic acid, such as geranic acid (which is a natural terpenoid), asthe degradation product), amide, ether, or amine linkage, such as whereR is has one of the following alternative structures:

—R₁₉—O—(C═O)—R₂₀  (reverse ester)

—R₁₉—(C═O)—NX—R₂₀  (amide)

—R₁₉—O—R₂₀  (ether)

—R₁₉—NX—R₂₀  (amine)

where R₁₉ and R₂₀ are as defined above and X is selected from hydrogen,alkyl, alkenyl, alkynyl, or aryl.

In embodiments, at least one of R₁-R₁₈, preferably at least one, such astwo or three, of R₃, R₇ and R₁₂, can have the followingaminoalkylcarboxy structure:

R₂₂R₂₃N—R₂₁—(C═O)—O—

where R₂₁ is substituted or unsubstituted alkyl and R₂₂ and R₂₃ areindependently selected from hydrogen, alkyl, alkenyl, alkynyl, and aryl.At least one of R₃, R₇ and R₁₂, preferably two or three of R₃, R₇ andR₁₂, is/are an aminoalkylester group, such as beta-alanine ester, whichforms an endogenous amino acid (e.g., beta-alanine) as degradationproduct (e.g., by hydrolysis of the R₃, R₇ and/or R₁₂ aminoalkylestergroup(s) at the C3, C7 and/or C12 position(s) of the sterol backbone).

It is within the scope of the invention to use other amino acidderivatives that form other naturally occurring amino acids asdegradation products, such as D-alanine, L-alanine, L-asparagine,D-aspartic acid, L-aspartic acid, L-cysteine, L-glutamic acid,L-glutamine, glycine, L-proline, D-serine, L-serine, L-tyrosine,L-arginine, L-histidine, L-isoleucine, L-leucine, L-lysine,D-methionine, L-methionine, L-phenylalanine, L-threonine, L-tryptophan,D-valine, L-valine, L-ornithine, hypusine, 2-aminoisobutyric acid,dehydroalanine, γ-aminobutyric acid, L-citrulline, α-ethyl-glycine,α-propyl-glycine, and L-norleucine.

The aminoalkyl group of at least one, such as one or two, of R₃, R₇, andR₁₂ can be attached to the sterol backbone by other linkages, such asamide or ether linkage, such as where R₁₈ has one of the followingalternative structures:

R₂₂R₂₃N—R₂₁—(C═O)—N—  (amide)

R₂₂R₂₃N—R₂₁—O—  (ether)

where R₂₁, R₂₂ and R₂₃ are as defined above.

Referring back to Formulae I, II and III, when the CSA compound has astructure of Formula I, m, n, p, and q are independently 0 or 1.

When the CSA compound has a structure of Formula I or II, rings A, B, C,and D are independently saturated, or are fully or partiallyunsaturated, provided that at least two of rings A, B, C, and D aresaturated.

R₁ through R₁₈ are independently selected from the group consisting ofhydrogen, hydroxyl, alkyl, hydroxyalkyl, alkyloxyalkyl,alkylcarbonylalkyl, terpenylcarboxyalkyl, terpenylcarbonyloxyalkyl,terpenylamidoalkyl, terpenylaminoalkyl, terpenyloxyoalkyl,alkylaminoalkyl, alkylaminoalkylamino, alkylaminoalkylaminoalkylamino,aminoalkyl, aryl, arylaminoalkyl, haloalkyl, alkenyl, alkynyl, oxo,linking group attached to a second steroid, aminoalkylurethanyl,aminoalkenylurethanyl, aminoalkynylurethanyl, aminoarylurethanyl,aminoalkyloxy, aminoalkylcarboxy, aminoalkyloxyalkyl,aminoalkylaminocarbonyl, aminoalkylcarboxamido, di(alkyl)aminoalkyl,H₂N—HC(Q₅)-(C═O)—O—, H₂N—HC(Q₅)-(C═O)—NH—, azidoalkyloxy, cyanoalkyloxy,P.G.-HN—HC(Q₅)-(C═O)—O—, guanidino-alkyloxy, quaternary ammoniumalkylcarboxy, and guanidinoalkyl carboxy, where Q₅ is a side chain ofany amino acid (including a side chain of glycine, i.e., H), and P.G. isan amino protecting group; and

R₅, R₈, R₉, R₁₀, R₁₃, R₁₄ and R₁₇ are independently deleted when one ofrings A, B, C, or D is unsaturated so as to complete the valency of thecarbon atom at that site,

provided that at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆,and R₁₈, preferably R₁₈, includes a terpenyl group, such as a geranylgroup, attached to the sterol backbone, e.g., at the C24 position, by anester linkage, amide linkage, ether linkage, or amine linkage, and

provided that at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆,and R₁₈, preferably one, two or three of R₃, R₇ and R₁₂, include(s) anamino acid attached to the sterol backbone, such as at the C3, C7 and/orC12 positions, by an ester linkage or amide linkage.

In embodiments, R₁ through R₁₈ are independently selected from the groupconsisting of hydrogen, hydroxyl, substituted or unsubstituted(C₁-C₂₂)alkyl, substituted or unsubstituted (C₁-C₂₂)hydroxyalkyl,substituted or unsubstituted (C₁-C₂₂)alkyloxy-(C₁-C₂₂)alkyl, substitutedor unsubstituted (C₁-C₂₂)alkylcarboxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarboxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarbonyloxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarboxamido-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylamino-(C₁-C₂₂)alkyl,(C₅-C₂₅)terpenyloxy-(C₁-C₂₂)alkyl, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkyl, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino, substituted orunsubstituted (C₁-C₂₂)aminoalkyl, substituted or unsubstituted aryl,substituted or unsubstituted arylamino-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₁-C₂₂)haloalkyl, substituted or unsubstituted(C₂-C₆)alkenyl, substituted or unsubstituted (C₂-C₆)alkynyl, oxo,linking group attached to a second steroid, substituted or unsubstituted(C₁-C₂₂)aminoalkylurethanyl, substituted or unsubstituted(C₂-C₂₂)aminoalkenylurethanyl, substituted or unsubstituted(C₂-C₂₂)aminoalkynylurethanyl, substituted or unsubstitutedaminoarylurethanyl, substituted or unsubstituted (C₁-C₂₂)aminoalkyloxy,substituted or unsubstituted (C₁-C₂₂)aminoalkylcarboxy, substituted orunsubstituted (C₁-C₂₂)aminoalkyloxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₁-C₂₂)aminoalkyl-aminocarbonyl, substituted orunsubstituted (C₁-C₂₂)aminoalkylcarboxamido, substituted orunsubstituted di(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkyl, H₂N—HC(Q₅)-(C═O)—O—,H₂N—HC(Q₅)-(C═O)—NH—, substituted or unsubstituted(C₁-C₂₂)azidoalkyloxy, substituted or unsubstituted(C₁-C₂₂)cyanoalkyloxy, P.G.-HN—HC(Q₅)-(C═O)—O—, substituted orunsubstituted (C₁-C₂₂)guanidinoalkyloxy, substituted or unsubstitutedquaternary ammonium (C₁-C₂₂)alkylcarboxy, and substituted orunsubstituted (C₁-C₂₂)guanidinoalkyl carboxy, where Q₅ is a side chainof an amino acid (including a side chain of glycine, i.e., H), and P.G.is an amino protecting group; and

R₅, R₈, R₉, R₁₀, R₁₃, R₁₄ and R₁₇ are independently deleted when one ofrings A, B, C, or D is unsaturated so as to complete the valency of thecarbon atom at that site,

provided that at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆,and R₁₈, preferably R₁₈, includes a (C₅-C₂₅)terpenyl group, such as ageranyl group, attached to the sterol backbone, e.g., at the C24position, by an ester linkage, amide linkage, ether linkage, or aminelinkage, and

provided that at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆,and R₁₈, preferably one, two or three of R₃, R₇ and R₁₂, include(s) anamino acid attached to the sterol backbone, such as at the C3, C7 and/orC12 positions, by an ester linkage or amide linkage.

In embodiments, R₁, R₂, R₄, R₅, R₆, R₈, R₉, R₁₀, R₁₁, R₁₃, R₁₄, R₁₅,R₁₆, and R₁₇ are independently selected from the group consisting ofhydrogen and unsubstituted (C₁-C₆) alkyl.

In embodiments, R₁, R₂, R₄, R₅, R₆, R₈, R₁₀, R₁₁, R₁₄, R₁₆, and R₁₇ areeach hydrogen and R₉ and R₁₃ are each methyl.

In embodiments, one or more of rings A, B, C, and D is/are heterocyclic.

In embodiments, rings A, B, C, and D is/are non-heterocyclic.

In embodiments, the CSA compound is a compound of Formula III, which isa subgenus of Formula I and Formula II with specified stereochemistry,wherein R₁, R₂, R₄, R₅, R₆, R₈, R₁₀, R₁₁, R₁₄, and R₁₆, are hydrogen ormethyl as shown, and R₁₅ is omitted:

where R₃, R₇, R₁₂, and R₁₈ are as defined above for Formula I and II,such as where:

R₁₈ has the following structure:

—R₁₉—(C═O)—O—R₂₀

where R₁₉ and R₂₀ are as defined above for Formula I and II, and

At least one, preferably two or three, of R₃, R₇ and R₁₂ has thefollowing aminoalkylcarboxy structure:

R₂₂R₂₃N—R₂₁—(C═O)—O—

where R₂₁, R₂₂ and R₂₃ are as defined above for Formula I and II.

In embodiments, where one or two of R₃, R₇, and R₁₂ independently has anaminoalkylcarboxy structure as defined herein, one or two of R₃, R₇, andR₁₂ are independently selected from the group consisting of hydrogen,(C₁-C₂₂)alkyl, (C₁-C₂₂)hydroxyalkyl, (C₁-C₂₂)alkyloxy-(C₁-C₂₂)alkyl,(C₁-C₂₂)alkylcarboxy-(C₁-C₂₂) alkyl, (C₁-C₂₂) alkylamino-(C₁-C₂₂)alkyl,(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino,(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino-(C₁-C₁₈)alkylamino,(C₁-C₂₂)aminoalkyl, arylamino-(C₁-C₂₂)alkyl, (C₁-C₂₂)aminoalkyloxy,(C₁-C₂₂)aminoalkylcarboxy, (C₁-C₂₂)aminoalkyloxycarbonyl,(C₁-C₂₂)aminoalkyloxy-(C₁-C₂₂)alkyl, (C₁-C₂₂)aminoalkylaminocarbonyl,(C₁-C₂₂)aminoalkylcarboxamido, di(C₁-C₂₂)alkylaminoalkyl,(C₁-C₂₂)guanidinoalkyloxy, quaternary ammonium (C₁-C₂₂)alkylcarboxy, and(C₁-C₂₂)guanidinoalkyl carboxy.

Preferably, where one or two of R₃, R₇, and R₁₂ independently has anaminoalkylcarboxy structure as defined herein, one or two of R₃, R₇, andR₁₂ are independently selected from the group consisting of hydrogen,(C₁-C₆)alkyl, (C₁-C₆)hydroxyalkyl, (C₁-C₁₆)alkyloxy-(C₁-C₅)alkyl,(C₁-C₁₆)alkylcarboxy-(C₁-C₅)alkyl, (C₁-C₁₆)alkylamino-(C₁-C₅)alkyl,(C₁-C₁₆)alkylamino-(C₁-C₅)alkylamino,(C₁-C₁₆)alkylamino-(C₁-C₁₆)alkylamino-(C₁-C₅)alkylamino, (C₁-C₁₆)aminoalkyl, arylamino-(C₁-C₅)alkyl, (C₁-C₅)aminoalkyloxy,(C₁-C₁₆)aminoalkyloxy-(C₁-C₅)alkyl, (C₁-C₅)aminoalkylcarboxy,(C₁-C₅)aminoalkyloxy carbonyl, (C₁-C₅)aminoalkylaminocarbonyl,(C₁-C₅)aminoalkylcarboxamido, di(C₁-C₅)alkylamino-(C₁-C₅)alkyl,(C₁-C₅)guanidinoalkyloxy, quaternary ammonium (C₁-C₁₆)alkylcarboxy, and(C₁-C₁₆)guanidinoalkylcarboxy.

In some embodiments, R₃, R₇, and R₁₂ are the same aminoalkylcarboxygroup.

In some embodiments, R₃, R₇, and R₁₂ are the same aminoalkylcarboxamidogroup.

In some embodiments, one or two of R₃, R₇, and R₁₂ are aminoalkyloxy.

In some embodiments, one or two of R₃, R₇, and R₁₂ areaminoalkylcarboxy.

A non-limiting example of an endogenous CSA compound that formsendogenous degradation products by hydrolysis of ester groups isCSA-148, and salts thereof:

In other embodiments, the geranyl group at the C24 position in R₁₈ canbe replaced with any other terpenyl moiety, such as those based on theexample terpenes set forth herein.

In other embodiments, the amino acid ester groups of R₃, R₇, and R₁₂ canbe replaced with any other amino acid ester groups, such as those basedon the example amino acids set forth herein.

Pharmaceutical Compositions

While CSA compounds described herein can be administered alone, it maybe preferable to formulate the compounds as pharmaceutical compositions(i.e., formulations). A pharmaceutical composition is any compositionthat may be administered in vitro or in vivo or both to a subject inorder to treat or ameliorate a condition. In a preferred embodiment, apharmaceutical composition may be administered in vivo. A subject mayinclude one or more cells or tissues, or organisms. In exemplaryembodiments, the subject is an animal. In embodiments, the animal is amammal. The mammal may be a human or primate in some embodiments. Amammal includes any mammal, such as by way of non-limiting example,cattle, pigs, sheep, goats, horses, camels, buffalo, cats, dogs, rats,mice, and humans.

“Pharmaceutically acceptable” and “physiologically acceptable” mean abiologically compatible formulation, gaseous, liquid or solid, ormixture thereof, which is suitable for one or more routes ofadministration, in vivo delivery, or contact. A formulation iscompatible in that it does not destroy activity of an active ingredienttherein (e.g., a CSA compound), or induce adverse side effects that faroutweigh any prophylactic or therapeutic effect or benefit.

Pharmaceutical compositions may be formulated with a pharmaceuticallyacceptable excipient, such as a carrier, solvent, stabilizer, adjuvant,diluent, etc., depending upon the particular mode of administration anddosage form. The pharmaceutical compositions can be formulated toachieve a physiologically compatible pH, and may range from about 3 to11, preferably about 3 to 7, depending on the formulation and route ofadministration. In alternative embodiments, the pH is adjusted to about5 to 8. The pharmaceutical compositions may comprise a therapeuticallyor prophylactically effective amount of at least one compound asdescribed herein, together with one or more pharmaceutically acceptableexcipients.

The pharmaceutical composition may comprise a combination of compoundsdescribed herein and/or may include a second active ingredient useful inthe treatment or prevention of bacterial infection (e.g., anti-bacterialor anti-microbial agents).

The composition can be formulated as a coating, such as on a medicaldevice. In embodiments, the coating is on a medical instrument.

Formulations for parenteral or oral administration can be solids, liquidsolutions, emulsions or suspensions. Inhalable formulations forpulmonary administration can be liquids or powders. A pharmaceuticalcomposition can be formulated as a lyophilized solid that isreconstituted with a physiologically compatible solvent prior toadministration. Alternative pharmaceutical compositions may beformulated as syrups, creams, ointments, tablets, etc.

Compositions may contain one or more excipients. Pharmaceuticallyacceptable excipients are determined in part by the particularcomposition being administered as well as by the particular method usedto administer the composition. There exists a wide variety of suitableformulations of pharmaceutical compositions (see, e.g., Remington'sPharmaceutical Sciences).

Suitable excipients may be carrier molecules that include large, slowlymetabolized macromolecules such as proteins, polysaccharides, polylacticacids, polyglycolic acids, polymeric amino acids, amino acid copolymers,and inactive virus particles. Other exemplary excipients includeantioxidants such as ascorbic acid; chelating agents such as EDTA;carbohydrates such as dextrin, hydroxyalkylcellulose,hydroxyalkylmethylcellulose, stearic acid; liquids such as oils, water,saline, glycerol and ethanol; wetting or emulsifying agents; pHbuffering substances; and the like. Liposomes are pharmaceuticallyacceptable excipients.

Pharmaceutical compositions may be formulated in any form suitable forthe intended method of administration. When intended for oral use forexample, tablets, troches, lozenges, aqueous or oil suspensions,non-aqueous solutions, dispersible powders or granules (includingmicronized particles or nanoparticles), emulsions, hard or softcapsules, syrups or elixirs may be prepared. Compositions intended fororal use may be prepared according to any method known to the art forthe manufacture of pharmaceutical compositions, and such compositionsmay contain one or more agents including sweetening agents, flavoringagents, coloring agents and preserving agents, in order to provide apalatable preparation.

Pharmaceutically acceptable excipients particularly suitable for use inconjunction with tablets include, for example, inert diluents, such ascelluloses, calcium or sodium carbonate, lactose, calcium or sodiumphosphate; disintegrating agents, such as cross-linked povidone, maizestarch, or alginic acid; binding agents, such as povidone, starch,gelatin or acacia; and lubricating agents, such as magnesium stearate,stearic acid or talc.

Tablets may be uncoated or may be coated by known techniques includingmicroencapsulation to delay disintegration and adsorption in thegastrointestinal tract and thereby provide a sustained action over alonger period. For example, a time delay material such as glycerylmonostearate or glyceryl distearate alone or with a wax may be employed.

Formulations for oral use may be also presented as hard gelatin capsuleswhere the active ingredient is mixed with an inert solid diluent, forexample celluloses, lactose, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredient is mixed with non-aqueousor oil medium, such as glycerin, propylene glycol, polyethylene glycol,peanut oil, liquid paraffin or olive oil.

Pharmaceutical compositions can be formulated as a suspension comprisinga CSA compound in admixture with at least one pharmaceuticallyacceptable excipient suitable for the manufacture of a suspension.

Pharmaceutical compositions can be formulated as dispersible powders andgranules suitable for preparation of a suspension by the addition ofsuitable excipients.

Excipients suitable for use in connection with suspensions includesuspending agents, such as sodium carboxymethylcellulose,methylcellulose, hydroxypropyl methylcellulose, sodium alginate,polyvinylpyrrolidone, gum tragacanth, gum acacia, dispersing or wettingagents such as a naturally occurring phosphatide (e.g., lecithin), acondensation product of an alkylene oxide with a fatty acid (e.g.,polyoxyethylene stearate), a condensation product of ethylene oxide witha long chain aliphatic alcohol (e.g., heptadecaethyleneoxycetanol), acondensation product of ethylene oxide with a partial ester derived froma fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitanmonooleate); polysaccharides and polysaccharide-like compounds (e.g.dextran sulfate); glycosaminoglycans and glycosaminoglycan-likecompounds (e.g., hyaluronic acid); and thickening agents, such ascarbomer, beeswax, hard paraffin or cetyl alcohol. The suspensions mayalso contain one or more preservatives such as acetic acid, methyland/or n-propyl p-hydroxy-benzoate; one or more coloring agents; one ormore flavoring agents; and one or more sweetening agents such as sucroseor saccharin.

Pharmaceutical compositions may be in the form of oil-in wateremulsions. The oily phase may be a vegetable oil, such as olive oil orarachis oil, a mineral oil, such as liquid paraffin, or a mixture ofthese. Suitable emulsifying agents include naturally-occurring gums,such as gum acacia and gum tragacanth; naturally occurring phosphatides,such as soybean lecithin, esters or partial esters derived from fattyacids; hexitol anhydrides, such as sorbitan monooleate; and condensationproducts of these partial esters with ethylene oxide, such aspolyoxyethylene sorbitan monooleate. The emulsion may also containsweetening and flavoring agents. Syrups and elixirs may be formulatedwith sweetening agents, such as glycerol, sorbitol or sucrose. Suchformulations may also contain a demulcent, a preservative, a flavoringor a coloring agent.

Pharmaceutical compositions may be in the form of a sterile injectablepreparation, such as a sterile injectable aqueous emulsion or oleaginoussuspension. The emulsion or suspension may be formulated according tothe known art using those suitable dispersing or wetting agents andsuspending agents which have been mentioned above. The sterileinjectable preparation may also be a sterile injectable solution orsuspension in a non-toxic parenterally acceptable diluent or solvent,such as a solution in 1,2-propandiol.

Sterile injectable preparations may also be prepared as a lyophilizedpowder. Among the acceptable vehicles and solvents that may be employedare water, Ringer's solution, and isotonic sodium chloride solution. Inaddition, sterile fixed oils may be employed as a solvent or suspendingmedium. For this purpose, any bland fixed oil may be employed includingsynthetic mono- or diglycerides. In addition, fatty acids such as oleicacid may likewise be used in the preparation of injectables.

To obtain a stable water-soluble dose form of a pharmaceuticalcomposition, a pharmaceutically acceptable salt of a compound describedherein may be dissolved in an aqueous solution of an organic orinorganic acid, such as 0.3 M solution of succinic acid, or morepreferably, citric acid. If a soluble salt form is not available, thecompound may be dissolved in a suitable co-solvent or combination ofco-solvents. Examples of suitable co-solvents include alcohol, propyleneglycol, polyethylene glycol 300, polysorbate 80, glycerin and the likein concentrations ranging from about 0 to 60% of the total volume. Inone embodiment, the active compound is dissolved in DMSO and dilutedwith water.

Pharmaceutical composition may also be in the form of a solution of asalt form of the active ingredient in an appropriate aqueous vehicle,such as water or isotonic saline or dextrose solution. Also contemplatedare compounds which have been modified by substitutions or additions ofchemical or biochemical moieties which make them more suitable fordelivery (e.g., increase solubility, bioactivity, palatability, decreaseadverse reactions, etc.), for example by esterification, glycosylation,PEGylation, and complexation.

Many therapeutics have undesirably short half-lives and/or undesirabletoxicity. Thus, the concept of improving half-life or toxicity isapplicable to various treatments and fields. Pharmaceutical compositionscan be prepared, however, by complexing the therapeutic with abiochemical moiety to improve such undesirable properties. Proteins area particular biochemical moiety that may be complexed with a CSA foradministration in a wide variety of applications. In some embodiments,one or more CSAs are complexed with a protein. In some embodiments, oneor more CSAs are complexed with a protein to increase the CSA'shalf-life. In other embodiments, one or more CSAs are complexed with aprotein to decrease the CSA's toxicity. Albumin is a particularlypreferred protein for complexation with a CSA. In some embodiments, thealbumin is fat-free albumin.

With respect to the CSA therapeutic, the biochemical moiety forcomplexation can be added to the pharmaceutical composition as 0.25,0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 10, 20, 50, or 100 weightequivalents, or a range bounded by any two of the aforementionednumbers, or about any of the numbers. In embodiments, the weight ratioof albumin to CSA is about 18:1 or less, such as about 9:1 or less. Inembodiments, the CSA is coated with albumin.

Non-biochemical compounds can be added to the pharmaceuticalcompositions to reduce the toxicity of the therapeutic and/or improvethe half-life. Suitable amounts and ratios of an additive that canreduce toxicity can be determined via a cellular assay. With respect tothe CSA therapeutic, toxicity reducing compounds can be added to thepharmaceutical composition as 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5,4, 4.5, 5, 10, 20, 50, or 100 weight equivalents, or a range bounded byany two of the aforementioned numbers, or about any of the numbers. Inembodiments, the toxicity reducing compound is a cocoamphodiacetate suchas Miranol® (disodium cocoamphodiacetate). In embodiments, the toxicityreducing compound is an amphoteric surfactant. In embodiments, thetoxicity reducing compound is a surfactant. In embodiments, the molarratio of cocoamphodiacetate to CSA is between about 8:1 and 1:1,preferably about 4:1. In embodiments, the toxicity reducing compound isallantoin.

In embodiments, a CSA composition is prepared utilizing one or moresurfactants. In specific embodiments, the CSA is complexed with one ormore poloxamer surfactants. Poloxamer surfactants are nonionic triblockcopolymers composed of a central hydrophobic chain of polyoxypropylene(polypropylene oxide)) flanked by two hydrophilic chains ofpolyoxyethylene (poly(ethylene oxide)). In some embodiments, thepoloxamer is a liquid, paste, or flake (solid). Examples of suitablepoloxamers include those by the trade names Synperonics, Pluronics, orKolliphor. In some embodiments, one or more of the poloxamer surfactantin the composition is a flake poloxamer. In embodiments, the one or morepoloxamer surfactant in the composition has a molecular weight of about3600 g/mol for the central hydrophobic chain of polyoxypropylene and hasabout 70% polyoxyethylene content. In embodiments, the ratio of the oneor more poloxamer to CSA is between about 50 to 1; about 40 to 1; about30 to 1; about 20 to 1; about 10 to 1; about 5 to 1; about 1 to 1; about1 to 10; about 1 to 20; about 1 to 30; about 1 to 40; or about 1 to 50.In embodiments, the ratio of the one or more poloxamer to CSA is between50 to 1; 40 to 1; 30 to 1; 20 to 1; 10 to 1; 5 to 1; 1 to 1; 1 to 10; 1to 20; 1 to 30; 1 to 40; or 1 to 50. In embodiments, the ratio of theone or more poloxamer to CSA is between about 50 to 1 to about 1 to 50.In embodiments, the ratio of the one or more poloxamer to CSA is betweenabout 30 to 1 to about 3 to 1. In some embodiments, the poloxamer isPluronic F127.

The amount of poloxamer may be based upon a weight percentage of thecomposition. In embodiments, the amount of poloxamer is about 10%, 15%,20%, 25%, 30%, 35%, 40%, about any of the aforementioned numbers, or arange bounded by any two of the aforementioned numbers or theformulation. In embodiments, the one or more poloxamer is between about10% to about 40% by weight of a formulation administered to the patient.In some embodiments, the one or more poloxamer is between about 20% toabout 30% by weight of the formulation. In embodiments, the formulationcontains less than about 50%, 40%, 30%, 20%, 10%, 5%, or 1% of CSA. Inembodiments, the formulation contains less than about 20% by weight ofCSA. The above described poloxamer formulations are particularly suitedfor the methods of treatment, device coatings, preparation of unitdosage forms (i.e., solutions, mouthwashes, injectables), etc.

In embodiments, the compounds described herein may be formulated fororal administration in a lipid-based formulation suitable for lowsolubility compounds. Lipid-based formulations can generally enhance theoral bioavailability of such compounds.

A pharmaceutical composition may comprise a therapeutically orprophylactically effective amount of a compound described herein,together with at least one pharmaceutically acceptable excipientselected from the group consisting of medium chain fatty acids orpropylene glycol esters thereof (e.g., propylene glycol esters of ediblefatty acids such as caprylic and capric fatty acids) andpharmaceutically acceptable surfactants such as polyoxyl 40 hydrogenatedcastor oil.

In embodiments, cyclodextrins may be added as aqueous solubilityenhancers. Preferred cyclodextrins include hydroxypropyl, hydroxyethyl,glucosyl, maltosyl and maltotriosyl derivatives of α-, β-, andγ-cyclodextrin. A particularly preferred cyclodextrin solubilityenhancer is hydroxypropyl-o-cyclodextrin (BPBC), which may be added toany of the above-described compositions to further improve the aqueoussolubility characteristics of the compounds of the embodiments. In oneembodiment, the composition comprises about 0.1% to about 20%hydroxypropyl-o-cyclodextrin, more preferably about 1% to about 15%hydroxypropyl-o-cyclodextrin, and even more preferably from about 2.5%to about 10% hydroxypropyl-o-cyclodextrin. The amount of solubilityenhancer employed will depend on the amount of the compound of theembodiments in the composition.

Synthesis

The methods disclosed herein may be as described below, or bymodification of these methods. Ways of modifying the methodologyinclude, among others, temperature, solvent, reagents etc., known tothose skilled in the art. In general, during any of the processes forpreparation disclosed herein, it may be necessary and/or desirable toprotect sensitive or reactive groups on any of the molecules concerned.This may be achieved by means of conventional protecting groups, such asthose described in Protective Groups in Organic Chemistry (ed. J. F. W.McOmie, Plenum Press, 1973); and P. G. M. Green, T. W. Wutts, ProtectingGroups in Organic Synthesis (3rd ed.) Wiley, New York (1999), which areboth hereby incorporated herein by reference in their entirety. Theprotecting groups may be removed at a convenient subsequent stage usingmethods known from the art. Synthetic chemistry transformations usefulin synthesizing applicable compounds are known in the art and includee.g. those described in R. Larock, Comprehensive OrganicTransformations, VCH Publishers, 1989, or L. Paquette, ed., Encyclopediaof Reagents for Organic Synthesis, John Wiley and Sons, 1995, which areboth hereby incorporated herein by reference in their entirety. Theroutes shown and described herein are illustrative only and are notintended, nor are they to be construed, to limit the scope of the claimsin any manner whatsoever. Those skilled in the art will be able torecognize modifications of the disclosed syntheses and to devisealternate routes based on the disclosures herein; all such modificationsand alternate routes are within the scope of the claims.

An exemplary but non-limiting general synthetic scheme for preparingcompounds of Formula I, Formula II, and Formula III is shown in SchemeA. Unless otherwise indicated, the variable definitions are as above forFormulae I, II and/or III.

Cholic acid (1) is treated with a terpenyl halide (e.g., geranylbromide) in a polar aprotic solvent (e.g., tetrahydrofuran) in thepresence of a base (e.g., potassium carbonate) to yield a terpenylcholate intermediate compound (2), e.g., geranyl cholate. The ester mayoptionally be modified, reduced, or protected, before or after any ofthe next steps, to yield a desired terpenyl linkage at the R₁₈ position.

The intermediate terpenyl (e.g., geranyl) cholate (2), or analogthereof, is treated with an N-protected amino acid (e.g., protected withtert-butyloxycarbonyl (Boc), fluorenylmethoxycarbony (Fmoc), orbenzylchloroformate (Cbz)) (e.g., Boc-beta-alanine) via carbodiimidecoupling using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI), oralternatively N,N′-dicyclohexylcarbodiimide (DCC), indimethylaminopyridine (DMAP) and methyl tert-butyl ether (MTBE) to yieldintermediate compound (3), or analog thereof, having a protectedaminoalkylcarboxy group at the C3, C7 and C12 positions of the sterolbackbone.

The intermediate compound (3), or analog thereof, is deprotected andacidified with hydrochloric acid in dioxane to form the acid additionsalt of the CSA compound (e.g., CSA-148 HCl).

In some embodiments, some or all of the foregoing steps can be performedin a one-pot reaction without purification of intermediate compounds.

In some embodiments, intermediate compound (2) is purified before usingit to make intermediate compound (3), and intermediate compound (3) ispurified and then treated with HCl in dioxane to deprotect the amine andform the HCl acid addition salt.

The HCl acid addition CSA salt can be purified and optionallyneutralized with a base, followed by separation (e.g., 2-phase liquidextraction followed by evaporation of organic solvent) to yield thepurified free base. The free base can be used as is or it can beacidified with any desired acid to form an acid addition salt.

An example acid addition salt is the salt of 1,5-naphthalenedisulfonicacid (1,5-NDSA salt, e.g., di-addition salt), which is highly insolubleand is therefore useful as a coating, such as a coating on animplantable medical device. In some cases, the NDSA salt is milled tosubmicron sized particles and put in a coating in particulate form. TheNDSA salt does not dissolve in ethylene oxide, which is commonly used tosterilize medical devices, and therefore can remain as a stable coatingafter multiple sterilization cycles.

Making the CSA compound ionic, such as by exchanging the NDSA portionwith other anions, e.g., chloride ions using HCl, sodium chloride, etc.,results in first order release kinetics, which can be accelerated inacidic conditions.

An advantage of the disclosed CSA compounds is that they degrade intoendogenous compounds, such as cholic acid, amino acid, and terpene.

EXAMPLES

The antimicrobial activity of CSA-148 was determined in comparison toCSA-44, a CSA compound known to have very high antimicrobial activitycompared to other CSAs. The microbes used in the comparative test waswere Candida albicans 90028, methicillin resistant Staphylococcus aureus(MRSA) BAA-41, and Pseudomonas aeruginosa (PA01 47085). The measuredminimum inhibitory concentrations (MICs) are set forth in Table 1.

TABLE 1 CSA Pathogen MIC 44 C. albicans 90028 8 μg/ml MRSA BAA-41 2μg/ml PA01 47085 2 μg/ml 148 C. albicans 90028 4 μg/ml MRSA BAA-41 2μg/ml PA01 47085 2 μg/ml

The measured MICs for C. albicans 90028 were based on 100% inhibition ofgrowth (i.e. no cloudiness). Judging by 50% inhibition, which is moredifficult but is typical for fungal MICs, the MIC for CSA-44 relative toC. albicans can be extrapolated to 4 μg/ml, and the MIC for CSA-148relative to C. albicans can be extrapolated to 2 μg/ml.

It was unexpected that CSA compounds within the scope of the inventioncan perform the same or better in killing microbes than CSAs that havebeen known and used for years even though they contain side groups withendogenous compounds.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed is:
 1. A cationic steroidal antimicrobial (CSA) compoundhaving a structure of Formula I or II, or a salt thereof:

where, m, n, p, and q are independently 0 or 1; rings A, B, C, and D areindependently saturated, or are fully or partially unsaturated, providedthat at least two of rings A, B, C, and D are saturated; R₁ through R₁₈are independently selected from the group consisting of hydrogen,hydroxyl, alkyl, hydroxyalkyl, alkyloxyalkyl, alkylcarboxyalkyl,terpenylcarboxyalkyl, terpenylcarbonyloxyalkyl, terpenylamidoalkyl,terpenylaminoalkyl, terpenyloxyoalkyl, alkylaminoalkyl,alkylamino-alkylamino, alkylaminoalkylaminoalkylamino, aminoalkyl, aryl,arylaminoalkyl, haloalkyl, alkenyl, alkynyl, oxo, linking group attachedto a second steroid, aminoalkylurethanyl, aminoalkenylurethanyl,aminoalkynylurethanyl, aminoarylurethanyl, aminoalkyloxy,aminoalkylcarboxy, aminoalkyloxyalkyl, aminoalkylaminocarbonyl,aminoalkylcarboxamido, di(alkyl)aminoalkyl, H₂N—HC(Q₅)-(C═O)—O—,H₂N—HC(Q₅)-(C═O)—NH—, azidoalkyloxy, cyanoalkyloxy,P.G.-HN—HC(Q₅)-(C═O)—O—, guanidino-alkyloxy, quaternary ammoniumalkylcarboxy, and guanidinoalkyl carboxy, where Q₅ is a side chain ofany amino acid (including a side chain of glycine, i.e., H), and P.G. isan amino protecting group; and R₅, R₈, R₉, R₁₀, R₁₁, R₁₄ and R₁₇ areindependently deleted when one of rings A, B, C, or D is unsaturated soas to complete the valency of the carbon atom at that site, providedthat at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆, and R₁₈,includes a terpenyl group attached to the sterol backbone by an esterlinkage, amide linkage, ether linkage, or amine linkage, and providedthat at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆, and R₁₈includes an amino acid attached to the sterol backbone by an esterlinkage or amide linkage.
 2. The CSA compound of claim 1, wherein atleast one of R₁-R₁₈ has a structure selected from:—R₁₉—(C═O)—O—R₂₀,—R₁₉—O—(C═O)—R₂₀,—R₁₉—(C═O)—NX—R₂₀,—R₁₉—O—R₂₀, and—R₁₉—NX—R₂₀, where R₁₉ is omitted or is selected from alkyl, alkenyl,alkynyl, and aryl, R₂₀ is a terpenyl group, and X is selected fromhydrogen, alkyl, alkenyl, alkynyl, or aryl.
 3. The CSA compound of claim1 or 2, wherein at least one of R₁-R₁₈ has a structure selected from:R₂₂R₂₃N—R₂₁—(C═O)—O—R₂₂R₂₃N—R₂₁—(C═O)—N—, andR₂₂R₂₃N—R₂₁—O— where R₂₁ is substituted or unsubstituted alkyl and R₂₂and R₂₃ are independently selected from hydrogen, alkyl, alkenyl,alkynyl, and aryl.
 4. The CSA compound of any one of claims 1 to 3,wherein: R₁ through R₁₈ are independently selected from the groupconsisting of hydrogen, hydroxyl, substituted or unsubstituted(C₁-C₂₂)alkyl, substituted or unsubstituted (C₁-C₂₂)hydroxyalkyl,substituted or unsubstituted (C₁-C₂₂)alkyloxy-(C₁-C₂₂)alkyl, substitutedor unsubstituted (C₁-C₂₂)alkylcarboxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarboxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarbonyloxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylcarboxamido-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₅-C₂₅)terpenylamino-(C₁-C₂₂)alkyl,(C₅-C₂₅)terpenyloxyo-(C₁-C₂₂)alkyl, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkyl, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino, substituted or unsubstituted(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkylamino, substituted orunsubstituted (C₁-C₂₂)aminoalkyl, substituted or unsubstituted aryl,substituted or unsubstituted arylamino-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₁-C₂₂)haloalkyl, substituted or unsubstituted(C₂-C₆)alkenyl, substituted or unsubstituted (C₂-C₆)alkynyl, oxo,linking group attached to a second steroid, substituted or unsubstituted(C₁-C₂₂)aminoalkylurethanyl, substituted or unsubstituted(C₂-C₂₂)aminoalkenylurethanyl, substituted or unsubstituted(C₂-C₂₂)aminoalkynylurethanyl, and substituted or unsubstitutedaminoarylurethanyl, substituted or unsubstituted (C₁-C₂₂)aminoalkyloxy,substituted or unsubstituted (C₁-C₂₂)aminoalkylcarboxy, substituted orunsubstituted (C₁-C₂₂)aminoalkyloxy-(C₁-C₂₂)alkyl, substituted orunsubstituted (C₁-C₂₂)aminoalkyl-aminocarbonyl, substituted orunsubstituted (C₁-C₂₂)aminoalkylcarboxamido, substituted orunsubstituted di(C₁-C₂₂)alkylamino-(C₁-C₂₂)alkyl, H₂N—HC(Q₅)-(C═O)—O—,H₂N—HC(Q₅)-(C═O)—NH—, substituted or unsubstituted(C₁-C₂₂)azidoalkyloxy, substituted or unsubstituted(C₁-C₂₂)cyanoalkyloxy, P.G.-HN—HC(Q₅)-(C═O)—O—, substituted orunsubstituted (C₁-C₂₂)guanidinoalkyloxy, substituted or unsubstitutedquaternary ammonium (C₁-C₂₂)alkylcarboxy, and substituted orunsubstituted (C₁-C₂₂)guanidinoalkylcarboxy, where Q₅ is a side chain ofan amino acid (including a side chain of glycine, i.e., H), and P.G. isan amino protecting group; and R₅, R₈, R₉, R₁₀, R₁₃, R₁₄ and R₁₇ areindependently deleted when one of rings A, B, C, or D is unsaturated soas to complete the valency of the carbon atom at that site, providedthat at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆, and R₁₈,includes a (C₅-C₂₅)terpenyl group attached to the sterol backbone by anester linkage, amide linkage, ether linkage, or amine linkage, andprovided that at least one of R₁ through R₄, R₆, R₇, R₁₁, R₁₂, R₁₅, R₁₆,and R₁₈, includes an amino acid attached to the sterol backbone by anester linkage or amide linkage.
 5. The CSA compound of any one of claims1 to 4, wherein R₁₈ includes a terpenyl group attached to the sterolbackbone at the C24 position by an ester linkage, amide linkage, etherlinkage, or amine linkage, and two or three of R₃, R₇ and R₁₂ is anamino acid attached to the sterol backbone by an ester linkage or amidelinkage.
 6. The CSA compound of any one of claims 1 to 5, wherein R₁₈has a structure selected from:—R₁₉—(C═O)—O—R₂₀,—R₁₉—O—(C═O)—R₂₀, and—R₁₉—(C═O)—NX—R₂₀, where R₁₉ is omitted or is selected from alkyl,alkenyl, alkynyl, and aryl, R₂₀ is a (C₅-C₂₅)terpenyl group, and X isselected from hydrogen, alkyl, alkenyl, alkynyl, or aryl.
 7. The CSAcompound of any one of claims 1 to 6, wherein R₃, R₇ and R₁₂ has astructure selected from:R₂₂R₂₃N—R₂₁—(C═O)—O—, andR₂₂R₂₃N—R₂₁—(C═O)—N— where R₂₁, R₂₂ and R₂₃ are the aminoalkylportion(s) of one or more naturally occurring amino acids.
 8. The CSAcompound of any one of claims 1 to 7, wherein the terpenyl group isformed from a terpene selected from the group consisting of:

one or more of:

one or more of

one or more of:


9. The CSA compound of any one of claims 1 to 8, wherein the amino acidis selected from the group consisting of D-alanine, L-alanine,L-asparagine, D-aspartic acid, L-aspartic acid, L-cysteine, L-glutamicacid, L-glutamine, glycine, L-proline, D-serine, L-serine, L-tyrosine,L-arginine, L-histidine, L-isoleucine, L-leucine, L-lysine,D-methionine, L-methionine, L-phenylalanine, L-threonine, L-tryptophan,D-valine, L-valine, L-ornithine, hypusine, 2-aminoisobutyric acid,dehydroalanine, γ-aminobutyric acid, L-citrulline, α-ethyl-glycine,α-propyl-glycine, and L-norleucine.
 10. The CSA compound of any one ofclaims 1 to 9, wherein the terpenyl group is a geranyl group.
 11. TheCSA compound of any one of claims 1 to 10, wherein the amino acid isbeta-alanine.
 12. The CSA compound of any one of claims 1 to 11, whereinR₁, R₂, R₄, R₅, R₆, R₈, R₉, R₁₀, R₁₁, R₁₃, R₁₄, R₁₅, R₁₆, and R₁₇ areindependently selected from the group consisting of hydrogen andunsubstituted (C₁-C₆) alkyl.
 13. The CSA compound of any one of claims 1to 12, wherein R₃, R₇, and R₁₂ are the same aminoalkylcarboxy group. 14.The CSA compound of any one of claims 1 to 13, wherein the CSA compoundhas a structure of Formula III:


15. The CSA compound of any one of claims 1 to 14, wherein the CSAcompound is selected fro CSA-148 and salts thereof:


16. A pharmaceutical composition comprising a CSA compound of any one ofclaims 1 to 15 and a pharmaceutically acceptable excipient selected froma carrier, solvent, stabilizer, adjuvant, and diluent.
 17. A method ofmanufacturing a CSA compound of any one of claims 1 to 15, comprising:treating cholic acid with a terpenyl compound in a polar aprotic solventand in the presence of a base to form a terpenyl cholate ester orterpenyl cholate amide intermediate compound having a terpenyl groupbonded to the C24 carbonyl via an ester or amide linkage, treating theterpenyl cholate ester or terpenyl cholate amide intermediate compoundwith an N-protected amino acid to yield a second intermediate compoundhaving a protected aminoalkylcarboxy group or protectedaminoalkylcarboxamido group at the C3, C7 and C12 positions of theterpenyl cholate ester or terpenyl cholate amide; optionally reducingthe C24 carbonyl to yield an ether or amine linkage for the terpenylgroup of R₁₈; and deprotecting the aminoalkylcarboxy group oraminoalkylcarboxamido group to yield the CSA compound or intermediatethereof.
 18. The method of claim 17, wherein deprotecting theaminoalkylcarboxy group or aminoalkylcarboxamido group includes treatingwith an acid (e.g., hydrochloric acid) to form an acid addition salt ofthe CSA compound.
 19. The method of claim 18, further comprisingneutralizing the acid addition salt of the CSA compound with a base andrecovering a free base of the CSA compound.
 20. The method of claim 19,further comprising acidifying the free base of the CSA compound with anacid to form a second acid addition salt of the CSA compound (e.g.,1,5-naphthalenedisulfonic acid di-addition salt).